From the German Pat. No. 25 14 794, there is known a sewing machine which is provided with an apparatus for sewing on an endless ribbon to a tube-like article. The article is advanced over a plurality of rollers arranged transversely to the advancing direction and whose axes can be varied in their distance. At least one of the rollers is driven by respective means. This apparatus in connection with the sewing machine provides an exact overlapped sewing of an endless ribbon on the article which is of low elasticity and allows an adjustment to articles of varying waist sizes.
The apparatus of this patent does not, however, permit an automatic adjustment of the transport of the article depending on the respective position of the non-stationary roller to compensate the different waist sizes of the articles. Moreover, this apparatus does not provide a temporary transport for advancing of the article.
German open application DE-OS No. 31 42 836 describes a sewing machine equipped with a tensioning apparatus for tube-like articles in which a stationary and a non-stationary tension roller is used. The non-stationary roller is supported on a lever with a counterbalance weight dimensioned in such a manner that an indifferent state is obtained on the lever. This apparatus does also lack the automatic adjustment of the advancing motion of the article in dependence on the respective position of the non-stationary roller.
German patent application P No. 33 12 317.9 and the above-mentioned U.S. Pat. No. 4,530,294 describe a sewing machine with a tension apparatus which includes a tension drum provided with at least three tension segments movable relative to the center of the tension drum. Since the drum must be arranged in front of the pressing foot of the sewing machine, it is not possible to stretch the tube-like article in immediate vicinty of the portion of the article to be sewed.